Carburetor



'Sept l, 1953 c. J. GREEN 2,650,582

Arrow/EVS' C. J. GREEN Sept. l, 1953 CARBURETOR 3 Sheets-Sheet 2 Filed Dec.' l, 1949 Sept. 1, 1953 Filed Dec. l, 1949 c. .1. GRI-:VEN 2,650,582

CARBURETOR 3 Sheets-Sheet '5 FROM MIX/N6 CHAMBER INVENMR, T'mf' J Green BY my, gaaf/M3555@ Afro/ww; vs

Patented Sept. 1, 1953 UNITED PATENT OFFICE 650,582 CARBURETOR rl fr. etten, bak niag, Tii. isp'piic'atioii December 1, 1949, srial N. 1305489 i2' claims. (c1. iisg-134) 1 This invention relates to carburetors of that type whose principle of operation vinvolvespreheating the air or heating the ,mixture Such carburetors commonly derive their heat from the exhaust 'of the engine.

Due to the large volume of air that has to pass in heat exchanging relation t'o a unit area of the exhaust in a given time on its way to the carburetor, there is not time for extensive heat ex change, and the air br the mixture orboth, as

the case may be, is inadequately heated to produce best results. ,l

The general object of the invention is to raise the effective temperature of the exhaust V`gases as a heat source for the carburetorr and to this end the principle of the Hilsch vortex or vortex tube is employed.

One of the objects of the invention is to pron vide a carburetor iii which the Hilsch vortex tube is used as a preheater for the air or mixture or both.

Another object of the invention is the, prevision of a carburetor wherein the Hilsch vortex tube is employed as a mixing device for the combustible mixture.

Still another object of the invention is to prem vide a Hilsch vortex tube heat exchanger adapted te serve as a preheater for a standard carburetor.

A further object of the inventionis to provide a. carburetor of novel construction incorporating the Hilsch vortex tube.

Other objects of the invention will, appear as the following description of operative embodiments thereof proceeds.

In the drawing in which' the iigures are largely diagrammatic, and in which the vsame reference characters have been used to denote identical parts:

Figure 1 is a section' in a longitudinal vertical plaine through a carburetor embodying the principies of the invention; y,

Figure 2 is a cross-section taken along the line 2--2 of Figure 1;

Figure 3 is a; longitudinal vertical Vsection through a carburetor employing a modifiedorm o'f Hilsch vortei'c` tube as ay preheater for the air and heater' for the fuel vaporvandl ,airy ,asu well as for a mixing device, part of the carburetor being omitted' but being similar to thecorrfesponding part of the carburetor shown in Figure l;

Figure 4 is a cro'ss'f-s'ectionY taken along the line lia-4' of Figure 3;

Before proceeding t a." detailed description of l the' several gues; a Hilsch vortex tube may be defined as a tube cf. some length; .having que, end restricted by a. plug WhichlQSeS thelelhearl portion' of Saidiubei but having allele the middleand havingtheother en d constricted by by a plug which closes the centralportiqn of the end of the tub.e,..but leavesppenthepf riphery. At a pointin the. lenethpt the.. .tube between the two piugs.,. b.l1,t relatively lclcsuehtp the plug having theI central 0p e ning an Hinput tube o'f re1ativeiy srna.ll diameterenterks the plugged tube tangentially.` Gas undernpressure is forced through theinputtube intothelualfger tube, the volume. beinasueh. that. .eitheind Q f the larger tube is inadequate. t0. discharge. it, .$0 that it issuesifrempqth .endepitheleree .tub-

Due. to the tangential. disngsition of. the .input tube,` the stream orugas-4 rotates hspirallyhgenerating a ZoneV of increased pressure near ,thewalls of the tube and azone 0L reduced pressure bout the axis or the tub e. .The axial gas andere@ by way of thecentral hole andthe peripheral ges .discharges bywavi `the peripheral. Opening- Bytheprinoiplee the Hilsch .vertex tub.., .wh ih is not fulvunderstood, thegas Whitt; issues f19m the central hole isf colder l the input gas, while the gas which contacts the periphery krOf the tube is hotter.. than. .theinput easf Hereinafter this4 tube will be referred to as the Hilsch vortex tube.. .This tube invented by a Frenchman, Remue. and further develgpd hype R 311.5941 of Germany.A The Frenchmans work wasurst announced 1933. the-, French. .Joel-naief Physics and RadiOlQev. D11- HilSChS .Work ,Wes uublishedin" an .articlf. .in the. February asil 0f the Reviewv of Scientific I nstruments," 1946.`

Bv the .Iilsch verter time input SaS/ S1191?. as theeehaust eas Of. aaiaternalgombustve engi@ at 800 E.Cenbe made .t provide@ A.peripheral gas temperature in thetube of 1, 2`0 0 E., the pertion of eas .discharging f Qm the Central .1151@ beine. correspondingly.reduced .t0 eben? 4.00.? 1","- Referrine nQWm detail@ the. Seifer@ glis and rstl to. that f olm 0f.. 6he. I1 Ye1li0i SHOW? in Figures .l andgzf thisiaa. Carburetor having a gasoline, chamber l.i..t.0.uhi.h.1i.qid. fuelsebplied by meant of a tendini La Centriuel Dump 3 beine illustratelfes'ameans .f Qr deiing' the fuel frornla supply. ilankmto the fuel chamber. Adjacent the gasclinechan'iberul, is a preheater which. as awholeis designated@ the numeral li, andV it comprises aal-lils'chvorte tube 5', having an end wall Sat its upper end withla central 1101@ .13., amiti?.- "f adjustable clos'ure at the other end, comprising edl periphery, and' having] an a valve i which closes the center of the tube but normally leaves an annular opening 3, the width of which may be adjustably varied responsive to temperature changes in the Hilsch vortex tube by means of a thermostat 9 to which the valve l is secured. The range of adjustment of the valve l includes complete closure of the end of the Hilsch vortex tube. The greater the restriction of the discharge through the annular opening 3, the higher will be the peripheral temperature of the tube 5.

The Hilsch vortex tube is made part of a heat exchanging device by means of the cylindrical shell I which surrounds it and is secured to it in fluid tight manner. Within the shell l is an intermediate cylindrical partition I I coaxial with the Hilsch vortex tube. dividing the shell into inner and outer concentric annular compartments I2 and I3. The inner compartment has a continuous fin I4, extending spirally therethrough throughout the length of said compartment, and the outer compartment is provided with a similar spiral iin I5. The shell lil, partition II and fins I4 and I5, as Well as the wall of the tube 5, are of metal and in intimate thermal Contact so as to derive the maximum amount of heat by conductivity from the Hilsch vortex tube. At a point relatively close to the upper end of the tube 5 and above the shell Iii, an input tube IE puts the exhaust manifold II of the engine in communication with the Hilsch vortex tube. The input tube I6 enters the tube 5 tangentially. Normally there is sufficient back pressure in the exhaust manifold of an engine to force exhaust gas under pressure through the input tube I6 into the Hilsch vortex tube. Part of the exhaust gas rotates spirally in a downward ldirection throughout the length of the tube 5,

densified by centrifugal force and discharging through the annular opening 8. Another attenuated part of the exhaust gas occupies an axial zone within the tube 5 and discharges through the central opening I8. The temperature of that part which contacts the wall of the tube 5 may be several hundred degrees higher in temperature than the input exhaust gas.

Atmospheric air enters the inner compartment i2 by way of a conduit I9, and traverses the spiral passage formed by the convolutions of the nn I4,V discharging at the bottom by way of a conduit 2B and perforated header 2|, below the level of the gasoline within the chamber I, hubbling to the surface of the gasoline becoming charged with gasoline vapor during its submerstruction employing the Wall of the exhaust manifold as a heat exchanging instrumentality with respect to the air constituent of the combustible mixture. The hot air issuing from the heater 2I warms the body of gasoline in the vchamber I, causing a rapid volatilization of the gasoline, so that the space Zla above the liquid fuel level is filled with gasoline vapor, which together with the air, is drawn into the lower end of the outer compartment through the hood 22. The metal surfaces which bound the spiral passage through the outer compartment are also heated by conduction, from the wall of the tube 5, but less severely than the surfaces of the inner compartment, since heat has been abstracted from the latter by the passage of the incoming air. The temperature of the surfaces of the outer compartment is generally high enough to increase the temperature of vthe mixture passing therethrough, which exits by way of the conduit 23, which leads to the induction side of a centrifugal pump 24. The mixture which passes through the outer compartment I3 may be termed a preliminary mixture, not completely homogeneous. It is delivered by the pump 24 to a mixing device, designated as a whole at 25. rThis also operates upon the principle of the Hilsch vortex tube, there being a tube 25 of relatively large diameter, having an end wall 21 near its upper end with central aperture 2S, the peripheral region of said end wall being closed. Near its opposite end the tube 26 is provided with a valve 29, mounted on a thermostat 30 located in an expanded portion 3| of the tube 26 and normally positioned in such a manner as to close the middle part of the lower end of the tube 26, but to leave open an annular passage 32. Essentially, the Hilsch vortex tube 25 is similar to the tube 5. The heated mixture from the pump 23 is forced by the pump through a Vconduit 33 of relatively small diameter, which opens into the tube 2c tangentially at a point adjacent the end, having the central hole 28. That part of the mixture which traverses the tube 26 peripherally in a centrifugal Whirl discharges through the annular opening 32. The rarer part which occupies an axial position in the tube discharges by Way of the central hole 28. The Walls of the tube 2E are not finned, and so there is not so much heat disssipation through said walls as in connection with tube 5, so that the peripheral mixture discharging through the annular passage 32 is very hot. The tube 2G is surrounded by a jacket spaced therefrom, with which the upper end of the tube 26 communicates and the expanded portion 3i of the tube 26 is provided with a plurality of inclined passages 35 therethrough, communicating with the space Within said jacket. Axial mixture discharges from the upper end of the tube 2G and traverses the jacketed space downwardly, picking up some heat, of course, from the wall of the tube 26 and passing through the passages 35 to mix with the hot mixture issuing from the annular passage 32. The mixing of the two fractions of the mixture at different temperatures and different densities produce an intimate and homogeneous mixture which may be considered optimum for complete combustion. The heated finished mixture passes through a conduit 35 and into the intake manifold 31, being drawn in by the suction within said manifold. The suction of the intake manifold alone may be relied upon for drawing the incoming air and the later developed combustible mixture through the entire carburetor system, but since a denite plus pressure is required in the tube 2t to make it function as a Hilsch vortex tube, the pump 24 is provided.

The pressure in the tube 2B will vary according to engine demands. When it exceeds a predetermined value, it forces open the check valve 33 at the bottom of the tube 26, the pressure being relieved by the return of some of the mixture through the conduit 39 back to the liquid fuel chamber. The conduit 39 is formed as a heat exchanging coil 40, submerged in the gasoline in `opposite passages at their lower ends.

5 the 'chamber l for heating said gasoline, the mixture issuing through a perforated header 4l below the liquid level of the gasoline, from which it bubbles up through the gasoline to occupy the space 2 l a and as much space as may be necessary within the outer compartment I3 of the heat exchanger.

For starting the engine when the latter is cold, a starting nozzle 42 is provided in the conduit 36, said nozzle being at the end of a tube G3 which dips below the level of the gasoline, as shown in Figure l. When the starting nozzle is operated, it is desirable to choke the carburetor, that is, to out on the incoming air, and when the carburetor is operating normally, that is, in a heated condition, the nozzle 42 is 'cut off. These functions are controlled by a thermostatic bulb 44 in the exhaust manifold, which operates a switch 45 in an electrical circuit, which includes the solenoids 46 and Lil', one operating the choke valve 48 `and the other a cut-off valve 49 in the tube 43, which supplies liquid fuel to the starting nozzle. The solenoids are so synchronized that one valve is closed simultaneously with the opening of the other.

ln Figures 3 and i a form of the invention is shown which is a modification of the carburetor illustrated in Figure l, to the extent that a different form of preheater is employed, together with such changes in the associated structure as are incident to the substitution.

in Figure 3, a metallic shell 5) surrounds the tube 5 in a fluid tight manner throughout a substantial length of said tube below the point at which the input tube it communicates within. This shell forms a single annular compartment about the tube E, the partition H present in the nrst described forni being omitted. Four parallel spiral fins 5l, ai, e3 and 5t define four gas pasextendi, the length of the shell 50. Figure fi shows that the four lins start at the upper end of the shell all, 96 displaced one from another. One pair of opposite passages are for the atmospheric air which comes in through the conduit I9. Therefore, said conduit is divided into branches 55 and be which open into opposite passages, as indicated in Figure 4. The other pair of opposite passages are for the passage of the mixture of air and fuel vapor formed in the upper part of the gasoline chamber l. Consequently, the hood Si which corresponds to the hood 22 in Figure l, is connected by two conduits 58 and 59 with said In this manner the air and fuel mixture passages alternate, fuel and air rising in the passages formed between fins 5l and 52 and 53 and 54, while air passes downwardly through the alternate passages. Thus, there is a counter current heat exchange.

As in `that form of the invention shown in Figure 1, the conduit 39 brings the relieved mixture from the mixingdevice 25 back to the perforated header 41, while the conduit 43 leads to the starting nozzle 42,

Since ,there is an optimum pressure at which the Hilsch vortex tube will operate with greatest emciency, the input tube i6 is provided with a valve ts which can be set at a definite optimum pressure value.

nvihile I have in the above description disclosed what l believe to be practical embodiments of my invention, it will be understood by those skilled in the art that the specific construction and arrangement of parts, as shown, are by way CII of example and not to be construed as limiting the scope of the invention.

What I claim as my invention is:

l. In a carburetor, a mixing chamber comprising a Hilsch vortex tube including a peripheral opening at one end and a central opening at the other, an input tube opening tangentially into said Hilsch vortex tube near the end having the central opening, means supplying a heated preliminary mixture of air and fuel vapor to said mixing chamber through said input tube, a jacket defining a jacketed space about said Hilsch vortex tube with which the end openings of the latter communicate, and a conduit between said jacketed space and the intake manifold of the engine opening into said jacketed space at a point adjacent tlie peripheral opening of said Hilsch vortex tube.

2. In a carburetor, a mixing chamber comprising a Hilsch vortex tube having a restricted openat one end, centrally located, and having means providing an annular peripheral opening of variable width at the other end, an input tube opening tangentially into said Hilsch vortex tube near the end having the central opening, means supplying a heated preliminary mixture of air and fuel vapor to said mixing chamber through said input tube, a vjacket defining a jacke'ted space about said l-iilsch vortex tube with which the end openings of said vortex tube communicate, and a conduit between said jacketed space and the intake manifold of the engine opening into said iacleted space at a'point adjacent the peripheral opening of said iilsch vortex tube.

3. In a carburetor as claimed in claim 2, the means which provides an annular peripheral opening of variable width at one end of said vortex tube being a thermostatically moved valve.

e. En a carburetor, a mixing chamber comprising a Hilsch vortex tube having a restricted opening at one end, centrally located, and having means providing an annular peripheral opening adjacent the other end, said Hilsch Vortex tube having an extension beyond said annular opening with perforations through its wall, an input tube opening tangentially into said Hilsch vortex tube near the end having the central opening, means supplying a heated preliminary mixture of air and fuel vapor to said mixing chamber through said input tube, a jacket defining a jacketed space about said Hilsch vortex tube and extension with which the end openings of said Hilsch vortex tube communicate, the peripheral opening communieating therewith through the perforations in the wall of said extension, and a conduit between said jaclreted space and the intake manifold of the origine opening into said iacketed space at a point adjacent the peripheral opening of said Hilsch vortex tube.

5. Carburetor comprising in serial connection, a heated intake air chamber, a liquid fuel chamber including a vapor space above the liquid level, and a mixing chamber communicating with the engine intake manifold, said heated intake air chamber comprising a Hilsch vortex tube having its input tube communicating with the exhaust manifold of the engine and an air passage opening to atmosphere in heat exchanging relationship to the wall of said Hilsch vortex tube, said air passage opening within said liquid fuel charnber below liquid fuel level, a conduit for mixing air and fuel vapor leading from the vapor space of said liquid fuel chamber to said mixing chamber, the latter comprising a Hilsch vortex tube with the input tube of which said conduit for mixed fuel vapor and air communicates, a jacket surrounding said second mentioned Hilsch vortex tube defining a jacketed space with which both ends of said second mentioned Hilsch vortex tube communicate and in which the relatively hot and dense, and relatively cold and attenuated portions of the mixture intimately commingle, a conduit between said jacketed space and the engine intake manifold, and a pump in the passage between said liquid fuel chamber and the input of said second mentioned Hilsch vortex tube.

6. Carburetor comprising in serial connection a heated intake air chamber, a liquid fuel chamber including a vapor space above the liquid level, and a mixing chamber communicating with the engine intake manifold, said heated intake air chamber comprising a Hilsch vortex tube having its input tube communicating with the exhaust manifold of the engine, and an air passage open to atmosphere in heat exchanging relationship.

with the Wall of said Hilsch vortex tube, said air passage opening within said liquid fuel chamber below liquid fuel level, and a conduit for mixing air and fuel vapor leading from the vapor space of said fuel chamber to said mixing chamber.

7. Carburetor including in serial connection a heated intake air chamber, a source of liquid fuel, and a mixing chamber, adapted to be connected to the engine intake manifold, said heated intake air chamber comprising a casing, a Hilsch vortex tube surrounded by said casing having its input tube adapted to be connected to the engine exhaust manifold, Said Hilsch vortex tube discharging to atmosphere, a baffle in said casing definin r with said casing and the Wall of said Hilsch vortex tube a circuitous passage for intake air open to atmosphere at its anterior end, and a conduit from the posterior end of said passage communicating with the source of liquid fuel.

3. Carburetor including a heater for intake air, and for a mixture of air and fuel vapor, said heater comprising a casing, a l-lilsch vortex tube passing through said casing having an input tube adapted to be connected to the engine exhaust manifold, an intermediate tubular partition within said casing dividing it into inner an-d outer annular compartments about said Hilsch vortex tube, spiral vanes in said compartments providing independent circuitous passages through said casing, said casing, partition and vanes being conductive and in heat exchanging relation with said i-lilsch vortex tube, said casing being provided with an atmospheric air inlet into the anterior end of the passage through said inner compartment, a liquid fuel chamber, a conduit from the posterior end of said passage to said liquid fuel chamber opening below liquid level therein, a conduit connecting the fuel chamber above liquid level with one end of the passage in the outer compartment, and a conduit communicating with the other end of said last named passage adapted t be finally connected to the engine intake manifold.

9. Carburetor including a heater for air and for a mixture of air and fuel vapor, said heater comprising a casing, a Hilsch vortex tube passing through said casing having its input tube adapted to be connected to the engine exhaust manifold, a plurality of parallel spiral vanes in said casing defining with the Hilsch vortex tube and the Wall of said casing circuitous passages therethrough, convolutions of one passage being alternatively disposed relative to convolutons 0f the other,

fio

,said .vanes and casing being conductive and in direct conductive relation to said Hilsch vortex tube, one of said passages being open to atmosphere at its anterior end, a liquid fuel chamber.

`the posterior end of sai-d last named passage opening -into said fuel chamber below the liquid level therein, the other passage communicating at one end with the liquid fuel chamber above the liquid level, and adapted to be finally connected to the engine intake manifold.

10. Carburetor including a heater for intake air and for a mixture of said heated intake air and fuel vapor, said heater comprising a casing, a Hilsch vortex tube passing through said casing having an input tube communicating With the engine exhaust manifold, partition structure Within said casing defining separate passages for intake air and for a mixture of saidy intake air and fuel vapor, the anterior end of one passage being open to atmosphere, a liquid fuel chamber, the posterior end of said last named passage communicating with said fuel chamber below the liquid level therein, one end of the other passage communicating with said liquid fuel chamber above the liquid level thereof, the opposite end of said other passa-ge communicating finally with the engine intake manifold.

11. In an hiternal combustion engine, a regenerative system for effectively utilizing the heat of the exhaust for heating the combustible mixture supplied to the engine, said system including a carburetor, a conduit leading thereto open to atmosphere and a combustible mixture conduit leading therefrom communicating with the engine intake manifold, and a Hilsch vortex tube having an input tube supplied by gaseous flow incident to the operation of the engine, the outer Wall of said Hilsch vortex tube being in heat exchanging relation to one 0f said conduits.

12. In an internal combustion engine, a regenerative system for effectively utilizing the heat of the exhaust for heating the combustible mixture supplied to the engine, said system including a carburetor, a conduit leading thereto open to atmosphere, and a combustible mixture conduit leading therefrom, two Hilsch vortex tubes serially related in said system in the order indicated, as regards their heat exchanging function, the first having an input tube communicating with the engine exhaust and in heat exchanging relation to one of said conduits, the second being intercalated in said combustible mixture conduit to form a part thereof having its input tube communicating With said conduit and its output tube communicating with the engine intake manifold.

CARL J. GREEN.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date 1,145,476 Fulton July 6, 1915 1,191,488 Watts July 18, 1916 1,392,473 Ball Oct. 4, 1921 1,731,135 Hutchison Oct. 8, 1929 1,742,732 Stenvig Jan. '7, 1930 1,763,508 Fowler June 10, 1930 1,865,514 Godward July 5, 1932 1,914,787 Puurmann June 20, 1933 1,952,281 Ranque Mar, 27, 1934 2,116,718 Stubbs May 10, 1938 2,384,609 De Vries Sept. 1l, 1945 

